Find the distance between the cities. Assume that Earth is a sphere of radius 4000 miles and that the cities are on the same longitude (one city is due north of the other).
City Latitude
1. Dallas, Texas 32° 47 9 N
Omaha, Nebraska 41° 15 50 N
2. San Francisco, California 37° 47 36 N
Seattle, Washington 47° 37 18 N